--- zzzz-none-000/linux-3.10.107/arch/powerpc/mm/pgtable_64.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/arch/powerpc/mm/pgtable_64.c 2021-02-04 17:41:59.000000000 +0000 @@ -33,10 +33,9 @@ #include #include #include -#include -#include #include #include +#include #include #include @@ -52,9 +51,13 @@ #include #include #include +#include #include "mmu_decl.h" +#define CREATE_TRACE_POINTS +#include + /* Some sanity checking */ #if TASK_SIZE_USER64 > PGTABLE_RANGE #error TASK_SIZE_USER64 exceeds pagetable range @@ -69,15 +72,11 @@ unsigned long ioremap_bot = IOREMAP_BASE; #ifdef CONFIG_PPC_MMU_NOHASH -static void *early_alloc_pgtable(unsigned long size) +static __ref void *early_alloc_pgtable(unsigned long size) { void *pt; - if (init_bootmem_done) - pt = __alloc_bootmem(size, size, __pa(MAX_DMA_ADDRESS)); - else - pt = __va(memblock_alloc_base(size, size, - __pa(MAX_DMA_ADDRESS))); + pt = __va(memblock_alloc_base(size, size, __pa(MAX_DMA_ADDRESS))); memset(pt, 0, size); return pt; @@ -111,10 +110,6 @@ __pgprot(flags))); } else { #ifdef CONFIG_PPC_MMU_NOHASH - /* Warning ! This will blow up if bootmem is not initialized - * which our ppc64 code is keen to do that, we'll need to - * fix it and/or be more careful - */ pgdp = pgd_offset_k(ea); #ifdef PUD_TABLE_SIZE if (pgd_none(*pgdp)) { @@ -153,6 +148,8 @@ } #endif /* !CONFIG_PPC_MMU_NOHASH */ } + + smp_wmb(); return 0; } @@ -224,7 +221,7 @@ if ((size == 0) || (paligned == 0)) return NULL; - if (mem_init_done) { + if (slab_is_available()) { struct vm_struct *area; area = __get_vm_area_caller(size, VM_IOREMAP, @@ -308,7 +305,7 @@ { void *addr; - if (!mem_init_done) + if (!slab_is_available()) return; addr = (void *) ((unsigned long __force) @@ -338,6 +335,34 @@ EXPORT_SYMBOL(__iounmap); EXPORT_SYMBOL(__iounmap_at); +#ifndef __PAGETABLE_PUD_FOLDED +/* 4 level page table */ +struct page *pgd_page(pgd_t pgd) +{ + if (pgd_huge(pgd)) + return pte_page(pgd_pte(pgd)); + return virt_to_page(pgd_page_vaddr(pgd)); +} +#endif + +struct page *pud_page(pud_t pud) +{ + if (pud_huge(pud)) + return pte_page(pud_pte(pud)); + return virt_to_page(pud_page_vaddr(pud)); +} + +/* + * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags + * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address. + */ +struct page *pmd_page(pmd_t pmd) +{ + if (pmd_trans_huge(pmd) || pmd_huge(pmd)) + return pfn_to_page(pmd_pfn(pmd)); + return virt_to_page(pmd_page_vaddr(pmd)); +} + #ifdef CONFIG_PPC_64K_PAGES static pte_t *get_from_cache(struct mm_struct *mm) { @@ -365,6 +390,10 @@ __GFP_REPEAT | __GFP_ZERO); if (!page) return NULL; + if (!kernel && !pgtable_page_ctor(page)) { + __free_page(page); + return NULL; + } ret = page_address(page); spin_lock(&mm->page_table_lock); @@ -379,9 +408,6 @@ } spin_unlock(&mm->page_table_lock); - if (!kernel) - pgtable_page_ctor(page); - return (pte_t *)ret; } @@ -455,3 +481,389 @@ } #endif #endif /* CONFIG_PPC_64K_PAGES */ + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + +/* + * This is called when relaxing access to a hugepage. It's also called in the page + * fault path when we don't hit any of the major fault cases, ie, a minor + * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have + * handled those two for us, we additionally deal with missing execute + * permission here on some processors + */ +int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp, pmd_t entry, int dirty) +{ + int changed; +#ifdef CONFIG_DEBUG_VM + WARN_ON(!pmd_trans_huge(*pmdp)); + assert_spin_locked(&vma->vm_mm->page_table_lock); +#endif + changed = !pmd_same(*(pmdp), entry); + if (changed) { + __ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry)); + /* + * Since we are not supporting SW TLB systems, we don't + * have any thing similar to flush_tlb_page_nohash() + */ + } + return changed; +} + +unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, unsigned long clr, + unsigned long set) +{ + + unsigned long old, tmp; + +#ifdef CONFIG_DEBUG_VM + WARN_ON(!pmd_trans_huge(*pmdp)); + assert_spin_locked(&mm->page_table_lock); +#endif + +#ifdef PTE_ATOMIC_UPDATES + __asm__ __volatile__( + "1: ldarx %0,0,%3\n\ + andi. %1,%0,%6\n\ + bne- 1b \n\ + andc %1,%0,%4 \n\ + or %1,%1,%7\n\ + stdcx. %1,0,%3 \n\ + bne- 1b" + : "=&r" (old), "=&r" (tmp), "=m" (*pmdp) + : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY), "r" (set) + : "cc" ); +#else + old = pmd_val(*pmdp); + *pmdp = __pmd((old & ~clr) | set); +#endif + trace_hugepage_update(addr, old, clr, set); + if (old & _PAGE_HASHPTE) + hpte_do_hugepage_flush(mm, addr, pmdp, old); + return old; +} + +pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + pmd_t pmd; + + VM_BUG_ON(address & ~HPAGE_PMD_MASK); + VM_BUG_ON(pmd_trans_huge(*pmdp)); + + pmd = *pmdp; + pmd_clear(pmdp); + /* + * Wait for all pending hash_page to finish. This is needed + * in case of subpage collapse. When we collapse normal pages + * to hugepage, we first clear the pmd, then invalidate all + * the PTE entries. The assumption here is that any low level + * page fault will see a none pmd and take the slow path that + * will wait on mmap_sem. But we could very well be in a + * hash_page with local ptep pointer value. Such a hash page + * can result in adding new HPTE entries for normal subpages. + * That means we could be modifying the page content as we + * copy them to a huge page. So wait for parallel hash_page + * to finish before invalidating HPTE entries. We can do this + * by sending an IPI to all the cpus and executing a dummy + * function there. + */ + kick_all_cpus_sync(); + /* + * Now invalidate the hpte entries in the range + * covered by pmd. This make sure we take a + * fault and will find the pmd as none, which will + * result in a major fault which takes mmap_sem and + * hence wait for collapse to complete. Without this + * the __collapse_huge_page_copy can result in copying + * the old content. + */ + flush_tlb_pmd_range(vma->vm_mm, &pmd, address); + return pmd; +} + +int pmdp_test_and_clear_young(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp) +{ + return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp); +} + +/* + * We currently remove entries from the hashtable regardless of whether + * the entry was young or dirty. The generic routines only flush if the + * entry was young or dirty which is not good enough. + * + * We should be more intelligent about this but for the moment we override + * these functions and force a tlb flush unconditionally + */ +int pmdp_clear_flush_young(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp) +{ + return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp); +} + +/* + * We mark the pmd splitting and invalidate all the hpte + * entries for this hugepage. + */ +void pmdp_splitting_flush(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp) +{ + unsigned long old, tmp; + + VM_BUG_ON(address & ~HPAGE_PMD_MASK); + +#ifdef CONFIG_DEBUG_VM + WARN_ON(!pmd_trans_huge(*pmdp)); + assert_spin_locked(&vma->vm_mm->page_table_lock); +#endif + +#ifdef PTE_ATOMIC_UPDATES + + __asm__ __volatile__( + "1: ldarx %0,0,%3\n\ + andi. %1,%0,%6\n\ + bne- 1b \n\ + ori %1,%0,%4 \n\ + stdcx. %1,0,%3 \n\ + bne- 1b" + : "=&r" (old), "=&r" (tmp), "=m" (*pmdp) + : "r" (pmdp), "i" (_PAGE_SPLITTING), "m" (*pmdp), "i" (_PAGE_BUSY) + : "cc" ); +#else + old = pmd_val(*pmdp); + *pmdp = __pmd(old | _PAGE_SPLITTING); +#endif + /* + * If we didn't had the splitting flag set, go and flush the + * HPTE entries. + */ + trace_hugepage_splitting(address, old); + if (!(old & _PAGE_SPLITTING)) { + /* We need to flush the hpte */ + if (old & _PAGE_HASHPTE) + hpte_do_hugepage_flush(vma->vm_mm, address, pmdp, old); + } + /* + * This ensures that generic code that rely on IRQ disabling + * to prevent a parallel THP split work as expected. + */ + kick_all_cpus_sync(); +} + +/* + * We want to put the pgtable in pmd and use pgtable for tracking + * the base page size hptes + */ +void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable) +{ + pgtable_t *pgtable_slot; + assert_spin_locked(&mm->page_table_lock); + /* + * we store the pgtable in the second half of PMD + */ + pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD; + *pgtable_slot = pgtable; + /* + * expose the deposited pgtable to other cpus. + * before we set the hugepage PTE at pmd level + * hash fault code looks at the deposted pgtable + * to store hash index values. + */ + smp_wmb(); +} + +pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) +{ + pgtable_t pgtable; + pgtable_t *pgtable_slot; + + assert_spin_locked(&mm->page_table_lock); + pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD; + pgtable = *pgtable_slot; + /* + * Once we withdraw, mark the entry NULL. + */ + *pgtable_slot = NULL; + /* + * We store HPTE information in the deposited PTE fragment. + * zero out the content on withdraw. + */ + memset(pgtable, 0, PTE_FRAG_SIZE); + return pgtable; +} + +/* + * set a new huge pmd. We should not be called for updating + * an existing pmd entry. That should go via pmd_hugepage_update. + */ +void set_pmd_at(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t pmd) +{ +#ifdef CONFIG_DEBUG_VM + WARN_ON((pmd_val(*pmdp) & (_PAGE_PRESENT | _PAGE_USER)) == + (_PAGE_PRESENT | _PAGE_USER)); + assert_spin_locked(&mm->page_table_lock); + WARN_ON(!pmd_trans_huge(pmd)); +#endif + trace_hugepage_set_pmd(addr, pmd_val(pmd)); + return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); +} + +void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0); +} + +/* + * A linux hugepage PMD was changed and the corresponding hash table entries + * neesd to be flushed. + */ +void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, unsigned long old_pmd) +{ + int ssize; + unsigned int psize; + unsigned long vsid; + unsigned long flags = 0; + const struct cpumask *tmp; + + /* get the base page size,vsid and segment size */ +#ifdef CONFIG_DEBUG_VM + psize = get_slice_psize(mm, addr); + BUG_ON(psize == MMU_PAGE_16M); +#endif + if (old_pmd & _PAGE_COMBO) + psize = MMU_PAGE_4K; + else + psize = MMU_PAGE_64K; + + if (!is_kernel_addr(addr)) { + ssize = user_segment_size(addr); + vsid = get_vsid(mm->context.id, addr, ssize); + WARN_ON(vsid == 0); + } else { + vsid = get_kernel_vsid(addr, mmu_kernel_ssize); + ssize = mmu_kernel_ssize; + } + + tmp = cpumask_of(smp_processor_id()); + if (cpumask_equal(mm_cpumask(mm), tmp)) + flags |= HPTE_LOCAL_UPDATE; + + return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags); +} + +static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot) +{ + pmd_val(pmd) |= pgprot_val(pgprot); + return pmd; +} + +pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot) +{ + pmd_t pmd; + /* + * For a valid pte, we would have _PAGE_PRESENT always + * set. We use this to check THP page at pmd level. + * leaf pte for huge page, bottom two bits != 00 + */ + pmd_val(pmd) = pfn << PTE_RPN_SHIFT; + pmd_val(pmd) |= _PAGE_THP_HUGE; + pmd = pmd_set_protbits(pmd, pgprot); + return pmd; +} + +pmd_t mk_pmd(struct page *page, pgprot_t pgprot) +{ + return pfn_pmd(page_to_pfn(page), pgprot); +} + +pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) +{ + + pmd_val(pmd) &= _HPAGE_CHG_MASK; + pmd = pmd_set_protbits(pmd, newprot); + return pmd; +} + +/* + * This is called at the end of handling a user page fault, when the + * fault has been handled by updating a HUGE PMD entry in the linux page tables. + * We use it to preload an HPTE into the hash table corresponding to + * the updated linux HUGE PMD entry. + */ +void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd) +{ + return; +} + +pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp) +{ + pmd_t old_pmd; + pgtable_t pgtable; + unsigned long old; + pgtable_t *pgtable_slot; + + old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0); + old_pmd = __pmd(old); + /* + * We have pmd == none and we are holding page_table_lock. + * So we can safely go and clear the pgtable hash + * index info. + */ + pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD; + pgtable = *pgtable_slot; + /* + * Let's zero out old valid and hash index details + * hash fault look at them. + */ + memset(pgtable, 0, PTE_FRAG_SIZE); + /* + * Serialize against find_linux_pte_or_hugepte which does lock-less + * lookup in page tables with local interrupts disabled. For huge pages + * it casts pmd_t to pte_t. Since format of pte_t is different from + * pmd_t we want to prevent transit from pmd pointing to page table + * to pmd pointing to huge page (and back) while interrupts are disabled. + * We clear pmd to possibly replace it with page table pointer in + * different code paths. So make sure we wait for the parallel + * find_linux_pte_or_hugepage to finish. + */ + kick_all_cpus_sync(); + return old_pmd; +} + +int has_transparent_hugepage(void) +{ + if (!mmu_has_feature(MMU_FTR_16M_PAGE)) + return 0; + /* + * We support THP only if PMD_SIZE is 16MB. + */ + if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT) + return 0; + /* + * We need to make sure that we support 16MB hugepage in a segement + * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE + * of 64K. + */ + /* + * If we have 64K HPTE, we will be using that by default + */ + if (mmu_psize_defs[MMU_PAGE_64K].shift && + (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1)) + return 0; + /* + * Ok we only have 4K HPTE + */ + if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1) + return 0; + + return 1; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */